import java.util.Scanner;

public class Main1632 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int a = n / 30;
        if (n > 30 && n % 30 == 0) {
            System.out.println(a);
        } else if (n > 30) {
            System.out.println(a + 1);
        } else {
            System.out.println(1);
        }

    }
}
